US10183745B2

Movatterモバイル変換

Info

Publication number: US10183745B2
Application number: US14/960,486
Authority: US
Inventors: Brent C Ross; Steven R Ivans
Original assignee: Bell Helicopter Textron Inc
Current assignee: Bell Helicopter Textron Inc
Priority date: 2015-12-07
Filing date: 2015-12-07
Publication date: 2019-01-22
Also published as: US20170158323A1; US11370535B2; US20190084669A1

Abstract

An aircraft is described and includes a fuselage, a wing coupled to the fuselage, and a rotor system including a proprotor system and an engine. An interconnect driveshaft gear is configured to communicate mechanical energy between a gearbox and an interconnect driveshaft. An accessory gear is coplanar with and in mechanical communication with the driveshaft gear. A proprotor gear is coplanar with and in mechanical communication with the interconnect driveshaft gear and the accessory gear and communicates mechanical energy to the proprotor system. An engine gear coplanar and in mechanical communication with the interconnect driveshaft ear, the accessory gear, and the proprotor gear transmits mechanical energy to the proprotor system via the proprotor gear.

Description

TECHNICAL FIELD

This invention relates generally to tiltrotor aircraft, and more particularly, to a tiltrotor with inboard engines.

BACKGROUND

A rotorcraft may include one or more rotor systems. One example of a rotorcraft rotor system is a main rotor system. A main rotor system may generate aerodynamic lift to support the weight of the rotorcraft in flight and thrust to counteract aerodynamic drag and move the rotorcraft in forward flight. A tiltrotor aircraft may include two rotor systems that can tilt upward to provide upward thrust or forward to provide forward thrust.

SUMMARY

Particular embodiments of the present disclosure may provide one or more technical advantages. A technical advantage of one embodiment may include the capability to move

rotor systems

110aand110btowards the tips ofwing150 so as to maximize the lengths of bothwing150 androtor blades120.

Certain embodiments of the present disclosure may include some, all, or none of the above advantages. One or more other technical advantages may be readily apparent to those skilled in the art from the figures, descriptions, and claims included herein.

BRIEF DESCRIPTION OF THE DRAWINGS

To provide a more complete understanding of the present invention and the features and advantages thereof, reference is made to the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 shows a tiltrotor aircraft with inboard pylons in accordance with teachings of the Prior Art;

FIG. 2A shows a tiltrotor aircraft with outboard pylons according to one example embodiment;

FIG. 2B shows the tiltrotor aircraft ofFIG. 2A in helicopter mode;

FIG. 2C shows the tiltrotor aircraft ofFIG. 2A with its wing and rotor blades folded away for storage;

FIGS. 3A-3C shows a gearbox configuration installed on the tiltrotor aircraft ofFIG. 2A according to one example embodiment; and

FIGS. 4A-4C shows a gearbox configuration installed on the tiltrotor aircraft ofFIG. 2A according to an alternative example embodiment.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows arotorcraft100. Rotorcraft100 features

rotor systems

110aand110b,blades120, afuselage130, alanding gear140, awing150, and anempennage160.

Rotor system110 may rotateblades120. Rotor system110 may include a control system for selectively controlling the pitch of eachblade120 in order to selectively control direction, thrust, and lift ofrotorcraft100.

In the example ofFIG. 1,rotorcraft100 represents a tiltrotor aircraft, and

rotor systems

110aand110bfeature

rotatable pylons

112aand112b. In this example, the position of

pylons

112aand112b, as well as the pitch ofrotor blades120, can be selectively controlled in order to selectively control direction, thrust, and lift oftiltrotor aircraft100. Power to

rotor systems

110aand110bis provided by

engines

114aand114b.

Fuselage

130 represents the main body ofrotorcraft100 and may be coupled to rotor system110 (e.g., via wing150) such that rotor system110 andblades120 may movefuselage130 through the air.Landing gear140 supportsrotorcraft100 when rotorcraft100 is landing and/or when rotorcraft100 is at rest on the ground.

In the example ofFIG. 1,tiltrotor aircraft100 may operate in a helicopter mode by tilting the pylons upright and in an airplane mode by tilting the pylons forward.Tiltrotor aircraft100 may generate greater forward speed in airplane mode than in helicopter mode because, in airplane mode,blades120 are oriented to generate greater thrust propelling the aircraft forward (somewhat analogous to a propeller).

Rotorcraft100 also features at least oneempennage160.Empennage160 represents a flight control surface coupled to the tail portion offuselage130. In the example ofFIG. 1,rotorcraft100 features twoempennage sections160. In this example, the combination of the twoempennage sections160 may represent a v-tail configuration.

Although appropriate for a variety of missions and settings, rotorcraft100 may present certain issues when it comes time for storage. For example, the length ofwing150 may be limited by the ability to fit into a small space, such as required when storing on a ship. However, reducing the length ofwing150 to accommodate these storage requirements may limit the length ofrotor blades120 because the tips ofrotor blades120 must remain a safe distance way fromfuselage130 during operation ofrotorcraft100.

Accordingly, teachings of certain embodiments recognize the capability to move

rotor systems

110aand110btowards the tips ofwing150 so as to maximize the lengths of bothwing150 androtor blades120. Teachings of certain embodiments recognize, however, that this may result in shorter flaperons, which may affect control of the rotorcraft.

FIGS. 2A-2C show a rotorcraft200 according to one example embodiments with its rotor systems located towards the tips of the wing.FIG. 2A shows rotorcraft200 in airplane mode,FIG. 2B shows rotorcraft200 in helicopter mode, andFIG. 2C shows rotorcraft200 with its wing and rotor blades folded away for storage.

In the example ofFIGS. 2A-2C, rotorcraft200 features

rotor systems

210aand210b,blades220, afuselage230, alanding gear240, awing250, and anempennage260. Some or all of these components may share similarities with components ofrotorcraft100 ofFIG. 1, such as

rotor systems

Unlikerotorcraft100, the

engines

214aand214bare located abovewing250, outboard offuselage230, and inboard of

respective pylons

212aand212b. Each

engine

214aand214balso features

respective inlets

216aand216bas well as associated

inlet barrier filters

218aand218b. Each

engine

214aand214bis in mechanical communication with an associated

pylon

212aand212bsuch that

engines

214aand214bprovides mechanical energy that causesblades220 to rotate. Like inrotorcraft100,

engines

214aand214bare fixed relative towing250.

FIGS. 3A-3C shows agearbox configuration300 installed on rotorcraft200 according to one example embodiment.FIGS. 3A and 3B show perspective views ofgearbox configuration300, andFIG. 3C shows an exploded view of the gearbox assembly ofgearbox configuration300.

In the example ofFIGS. 3A-3C,gearbox configuration300 features agearbox310 and aninterconnect drive shaft320. Theexample gearbox configuration300 is shown inFIGS. 3A-3C installed with respect topylon212bandengine214b, but teachings of certain embodiments recognize thatgearbox configuration300 could also be installed with respect topylon212aandengine214a.

As seen in the examples ofFIGS. 3A-3B,gearbox310 is located inboard ofpylon212band is fixed relative towing250 such thatgearbox310 does not rotate withpylon212b. In the example ofFIG. 3C,gearbox310 features aninterconnect driveshaft gear312, interconnect gears314a, accessory gears314b, aproprotor gear316, and anengine gear318.Interconnect driveshaft gear312 is configured to communicate mechanical energy withinterconnect driveshaft320, accessory gears314 are configured to communicate mechanical energy with accessory devices (such as generators are pumps), interconnect gears314aare configured to communicate mechanical energy betweeninterconnect driveshaft gear312 andproprotor gear316, proprotor gear316bis configured to communicate mechanical energy withpylon212b, andengine gear318 is configured to receive mechanical energy fromengine214b. In this example, each of these gears are coplanar, although teachings of certain embodiments recognize that other configurations may be used.

Interconnect drive shaft

320 provides mechanical communication between

engines

214aand214bsuch that, if one engine fails, the other engine can power both

pylons

212aand212b.Interconnect drive shaft320 is installed at least partially withinwing250. More specifically, as seen in the examples ofFIGS. 3A and 3B,interconnect drive shaft320 is located between two

rear spars

252band252cofwing250 and passes through openings inwing ribs254 spread out acrosswing250. As seen in the example ofFIG. 3B, spars252aand252bandribs254 intersect to definewing torque boxes256. In some embodiments,gearbox310 is positioned adjacent to and about aspar252bsuch thatgearbox310 does not intrude into atorque box256. Examples of such intrusions may include residing within the interior portion of atorque box256 or protruding through aspar252borrib254 such that the structural strength of atorque box256 is reduced.

In operation, according to one example embodiment, power is transmitted from the engine through a spiral bevel into the clutch and into a helical gear train that connects the interconnect drive shaft and conversion axis spindle gearbox, which are offset vertically and fore and aft. Accessories for hydraulic and power systems are also mounted and run on the helical train. The interconnect gearbox may allow an offset between the spiral bevel from the engine such that a removable floating quill shaft can join the fixed and rotating drive systems. Teachings of certain embodiments recognize that such an arrangement may allow for servicing of the critical shaft that bridges rotating to fixed drive systems. The spindle gearbox, which rotates, is supported by extensions containing bearings above the wing of the two outboard tip ribs and connects to the floating quill shaft. A spiral bevel at the center of the spindle gear box provides power to a dual planetary reduction to final mast speeds.

The wing torque box with intermediate ribs support the engine, fixed drive system, and rotating pylon interfaces. The interconnect gearbox is mounted to the top of wing torque box with a bellhousing connecting the transmission and the inboard tip rib at the conversion axis providing a rigid attachment. The tip ribs extend above the wing and the upper portion of the rib is removable with a pillow block arrangement with tension or shear attachments possible for pylon removal.

FIGS. 4A-4C shows a gearbox configuration400 installed on rotorcraft200 according to an alternative example embodiment.FIGS. 4A and 4B show perspective views of gearbox configuration400, andFIG. 4C shows an exploded view of the gearbox assembly of gearbox configuration400.

In the example ofFIGS. 4A-4C, gearbox configuration400 features agearbox410 and aninterconnect drive shaft420. Theexample gearbox configuration300 is shown inFIGS. 4A-4C installed with respect topylon212bandengine214b, but teachings of certain embodiments recognize that gearbox configuration400 could also be installed with respect topylon212aandengine214a.

As seen in the examples ofFIGS. 4A-4B,gearbox410 is located outboard ofpylon212band is fixed relative towing250 such thatgearbox410 does not rotate withpylon212b. In the example ofFIG. 4C,gearbox410 features aninterconnect driveshaft gear412, interconnect gears414a, accessory gears414b, aproprotor gear416,proprotor shafts417, and anengine gear418.Interconnect driveshaft gear412 is configured to communicate mechanical energy withinterconnect driveshaft420, interconnect gears414aare configured to communicate mechanical energy betweeninterconnect driveshaft gear412 andproprotor gear416, accessory gears414bare configured to communicate mechanical energy with accessory devices (such as generators or pumps),proprotor gear416 is configured to communicate mechanical energy withpylon212b, andengine gear418 is configured to receive mechanical energy fromengine214b.Proprotor shafts417 are coupled toproprotor gear416 and pass through a portion ofpylon212band couple toengine gear418. In this example,interconnect driveshaft gear412, accessory gears414, andproprotor gear416 are coplanar, although teachings of certain embodiments recognize that other configurations may be used.Gearbox configurations300 and400 may provide a number of relative advantages. For example,gearbox configuration300 may provide improved accessibility for workers responsible for maintaining or repairing components associated with

pylons

212aand212b. Gearbox configuration400, on the other hand, may provide additional space for accessories, such as generators or hydraulic pumps by movinggearbox410 to an outboard location and away from the space constraints imposed bywing250.

Modifications, additions, or omissions may be made to the systems and apparatuses described herein without departing from the scope of the invention. The components of the systems and apparatuses may be integrated or separated. Moreover, the operations of the systems and apparatuses may be performed by more, fewer, or other components. The methods may include more, fewer, or other steps. Additionally, steps may be performed in any suitable order.

Although several embodiments have been illustrated and described in detail, it will be recognized that substitutions and alterations are possible without departing from the spirit and scope of the present invention, as defined by the appended claims.

To aid the Patent Office, and any readers of any patent issued on this application in interpreting the claims appended hereto, applicants wish to note that they do not intend any of the appended claims to invoke paragraph 6 of 35 U.S.C. § 112 as it exists on the date of filing hereof unless the words “means for” or “step for” are explicitly used in the particular claim.

Claims

What is claimed is:

1. An aircraft, comprising:

a fuselage;

a wing coupled to the fuselage;

a first rotor system coupled to the wing, the first rotor system comprising:

a first proprotor system comprising a first pylon disposed proximate to a first wing tip of the wing, the first pylon being tiltable between a helicopter mode position and an airplane mode position;

a first engine in mechanical communication with the first proprotor system and coupled above the wing proximate to the first wing tip, outboard of the fuselage, and inboard of the first pylon;

a second rotor system coupled to the wing, the second rotor system comprising:

a second proprotor system comprising a second pylon disposed proximate to a second wing tip of the wing opposite the first wing tip, the second pylon being tiltable between a helicopter mode position and an airplane mode position; and

a second engine in mechanical communication with the second proprotor system and coupled above the wing proximate to the second wing tip, outboard of the fuselage, and inboard of the second pylon;

one or more interconnect drive shafts in mechanical communication with the first and second engines;

a first gearbox in mechanical communication with the first engine, the first proprotor system, and the one or more interconnect drive shafts; and

a second gearbox in mechanical communication with the second engine, the second proprotor system, and the one or more interconnect drive shafts;

an interconnect driveshaft gear configured to communicate mechanical energy between the first gearbox and the one or more interconnect driveshafts;

one or more accessory gears coplanar with and in mechanical communication with the interconnect driveshaft gear;

a proprotor gear located inboard of the first proprotor system, the proprotor gear being coplanar with and in mechanical communication with the interconnect driveshaft gear and the one or more accessory gears, the proprotor gear configured to communicate mechanical energy to the first proprotor system; and

an engine gear coplanar with and in mechanical communication with the interconnect driveshaft gear, the one or more accessory gears, and the proprotor gear, the engine gear configured to transmit mechanical energy from the first engine to the first proprotor system via the proprotor gear.

2. The aircraft ofclaim 1, wherein the first and second engines are fixed relative to the wing.

3. The aircraft ofclaim 1, wherein the first and second gearboxes are fixed relative to the wing.

4. The aircraft ofclaim 1, wherein:

the first gearbox is in mechanical communication between the first engine and the first proprotor system; and

the second gearbox is in mechanical communication between the second engine and the second proprotor system.

5. The aircraft ofclaim 1, wherein the first gearbox is located inboard of the first proprotor system proximate to the first wing tip and the second gearbox is located inboard of the second proprotor system proximate to the second wing tip.

6. The aircraft ofclaim 1, the wing comprising:

a first wing spar;

a second wing spar;

a first wing rib coupled and substantially perpendicular to the first and second wing spars; and

a second wing rib coupled and substantially perpendicular to the first and second wing spars, wherein:

the first wing spar, the second wing spar, the first wing rib, and the second wing rib form, in combination, a torque box; and

the first gearbox is positioned adjacent to and about the first wing spar such that the first gearbox does not intrude into the torque box.

7. The aircraft ofclaim 1, wherein:

the first proprotor system is in mechanical communication between the first engine and the first gearbox; and

the second proprotor system is in mechanical communication between the second engine and the second gearbox.

8. The aircraft ofclaim 1, wherein the first gearbox is located outboard of the first proprotor system and the second gearbox is located outboard of the second proprotor system.

9. The aircraft ofclaim 1, wherein the first gearbox receives mechanical energy from the first engine via the first proprotor system.

10. An aircraft, comprising:

a fuselage;

a wing coupled to the fuselage;

a first rotor system coupled to the wing, the first rotor system comprising:

a first proprotor system comprising a first pylon coupled proximate to a first wing tip of the wing, the first pylon being tiltable between a helicopter mode position and an airplane mode position;

a first engine in mechanical communication with the first proprotor system and coupled above the wing, outboard of the fuselage and inboard of a first pylon;

a second rotor system coupled to the wing, the second rotor system comprising:

a second proprotor system comprising a second pylon coupled proximate to a second wing tip of the wing opposite the first wing tip, the second pylon being tiltable between a helicopter mode position and an airplane mode position; and

a second engine in mechanical communication with the second proprotor system and coupled above the wing, outboard of the fuselage, and inboard of the second pylon;

wherein the first gearbox comprises:

11. An aircraft, comprising:

a fuselage;

a wing coupled to the fuselage;

a first rotor system coupled to the wing, the first rotor system comprising:

a second rotor system coupled to the wing, the second rotor system comprising:

wherein the first gearbox comprises:

a proprotor gear located outboard of the first proprotor system, the proprotor gear being coplanar with and in mechanical communication with the interconnect driveshaft gear and the one or more accessory gears, the proprotor gear in mechanical communication with the first proprotor system;

one or more proprotor shafts coupled to the proprotor gear and passing through the first proprotor system; and

an engine gear coupled to the one or more proprotor shafts and configured to provide mechanical energy from the first engine to the first proprotor system and the proprotor gear.